The Tasmanian Government is being accused of using its compulsory acquisition powers to clear the way for timber company Gunns to build a pipeline for its proposed pulp mill.

The Department of Infrastructure, Energy and Resources (DIER) says it is buying land to build a new road and the fact that there will also be room for Gunns' water pipe is incidental.

The proposed road will run through the Tamar Valley, near Launceston, where several locals have been refusing to sell their property to the controversial timber company.

But DIER is now using its compulsory acquisition powers to get that land for a new road.

Roads and Traffic general manager Peter Todd says he has been speaking to Gunns about laying its pipeline alongside the road.

"We have been in discussion with them in accordance to the pulp mill permit," he said.

"They're looking at where they might run the pipeline. So we've had discussions with them about the whole route of the pipeline."

Mr Todd says the department has been discussing running the two projects in parallel for around three years.

But he says Gunns is yet to formally ask for permission to build the pipeline near the road.

The acquisition will affect three landowners, who did not want to be interviewed.

It is understood they are trying to discover if the department is increasing the size of the road acquisition to incorporate Gunns' pipeline.

At the Gunns annual general meeting last year the company told shareholders all problems with landowner opposition to the pipeline had been overcome.

But Gunns will not comment on the government's land acquisition.

Mr Todd says the acquisition is primarily for the road.

"We've been working on this as a roads project and it's had nothing to do with whether Gunns or anyone else wants to put infrastructure in," he said.

"They've approached us but we've acquired land only for construction of the road."

Mr Todd says Gunns approached the government before the land was acquired.

"The project was announced and there was a corridor that was in the public domain as to where it would be and then we started the acquisition process. That process takes some months," he said.

But Greens MP Kim Booth says the government is helping Gunns.

"Tasmanians and land owners in particular should be very, very concerned ... about the spectre of Gunns simply being able to get the government to seize private property for their own private purposes," he said.

"It really begs the point as to who the government is working for.

"Is the government working for the people of Tasmania, are they working for Gunns, or is in fact Gunns the government?"

Premier David Bartlett says he is unaware of the negotiations between Gunns and DIER.